Sheet feeding mechanism for printing machines



SHEET FEEDING MEGHANISM FOR PRINTING MACHINES Dec. 26, 1933.

Dec. 26, 1933. x, A. HUNTING SHEET FEEDING MECHANISM FOR PRINTINGMACHINES Filed Nov. 16, 1928 5 Sheets-Sheet 2 mvEN-ron l z/f' Dec. 26,1933. A. HUNTING 1,941,093

SHEET FEEDING MECHANISM FOR PRINTING MACHINES Filed Nov. 16, 1928 5Sheets-Sheet 3 INVENTGR Dec. 26, 1933. I l. A. HUNTING 1,941,093

SHEET FEEDING MECHANISM FOR PRINTING MACHINES Filed Nov. 16. 1928 5Sheets-Sheet 4 INVEN'T'QF!v Dec. 26, 1933.

i. A. HUNTING SHEET FEEDING MECHANISM FOR PRINTING MACHINES Filed NOV.16. 1928 5 Sheets-Shea?l 5 INVEN'I'QR Patented Dec.. 26, 1933 UNITEDSTATES PATENT oFFlcE SHEET FEEDING MECHANISM FOR PRINTING MACHINES pany,receiver Application November 18, 1928 Serial No. 319,815

7 Claims.

'I'he invention herein disclosed relates to feeding devices for printingmachines adapted to print on sheet metal, pasteboard and similarmaterials. Printing machines of this class have heretofore been madewith a feed table on which the operator places a sheet to be printed, asheet guide and suitable forwarding mechanism which serves to convey thesheet from the feed table to the printing cylinders. In these machinesthe sheet guide is in alignment with the bite of the cylinders and apusher engages the rear edge of the sheet to move it forward to thecylinders. In order that the pusher does not obstruct the sheet as itpasses from the feed table to the sheet guide, the feed table is placedon a higher level and the sheet in passing from the feed table to thesheet guide is projected forward and drops on the sheet guide in frontof the pusher. The invention disclosed herein constitutes an improvementin feeding mechanism of this class, for the feed table is here placed inalignment with the sheet guides and a mechanism is provided that removesthe pusher from the p-..th of the oncoming sheet. From the time thesheet starts from the feed table, until it is printed, it is at alltimes, rigidly held and its motion perfectly controlled. It is thuspossible to obtain accurate register in the printing when the inventiondisclosed herein is used.

In addition to being used with printing machines that are fed manually,this invention is also applicable to machines that are equipped withautomatic feeders.

An object of the invention is to provide a feeding mechanism for aprinting machine of the class described in which the motion of the sheetwill be perfectly controlled during the time it is passing from the feedtable or from the feeder to the printing cylinders.

Another object of the invention is to provide a feeding mechanism thatwill present the sheet to the cylinders in a manner to effect accurateregister of the printing.

It is also an object of the invention to provide a feeding mechanism ofgenerally improved construction, whereby the device will be simple,durable and inexpensive in construction, as well as convenient,practical, serviceable and efficient` in its use.

With the foregoing and other objects in view, which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts, and in the details of construction hereinafterdescribed and claimed, it

being understood that various changes in the precise embodiment of theinvention herein disclosed may be made within the scope of what isclaimed without departing from the spirit of the invention.

Figure 1 of the drawings is a side view of a portion of a printingmachine showing the improved sheet feeding device and mechanism by whichit is operated, the parts being shown in the position they occupy when asheet is being fed into the bite of the printing cylinders.

Figure 2 is a view similar to Figure 1, but showing the parts as theyappear when a sheet is being forwarded along the sheet guide.

Figure 3 is a sectional view on the line 3-3 70 of Figure 1 as viewed inthe direction of the arrow.

Figure 4 is a detail side view of the pusher which forwards the sheet tothe printing cylinders.

Figure 5 is a back view of the pusher as seen in the direction of arrow5 in Figure 4; and

Figure 6 is a side view in outline of a printing machine of this classequipped with an automatic feeder.

Referring'to the drawings, 11 and 11 indicate the main side frames of aprinting machine and 12 a support for a feed table 13. A sheet guide 14has one of its ends in horizontal alignment with the feed table and theother end in alignment with the bite of the printing cylinders 15 and16, it being understood that 15 indicates a cylinder carrying thevoffset blanket commonly used for this class of work, and 16 indicatesthe impression cylinder having grippers 1'7, that 90 are provided withregistering faces or stops 17' which engage the front edge of the sheet.These registering grippers are secured to the shaft 18 and are operatedby the cam 19, secured to the frame 11. This cam acts on the roller 20car- 95 ried on arm 21 which is also secured to shaft 18.

Forwarding rollers 22 and 23 are connected together by the gear train24, and may be driven by a chain which passes around the idlers 25 and26, and is driven by the sprocket 27, connected to the gear 28, meshingwith the gear 29 on the main shaft 30. Drop rollers 31 and 32 arecarried in bell crank levers 33 and 34, pivoted respectively at 35 and36 in the members 3'7 and 38. The thumb nuts 39 and 40, 105 serve toadjust the position of the drop rollers4 with relation to the members 37and 38, which are secured to the shafts 41 and 42, and thus adjust thepressure of the drop rollers against the sheet being forwarded.

' described and indicated at '72.

Arm 43 is secured to shaft 42 and connected by link 44 with arm 45,pivoted on the stud l46 and carrying roller 4'7, which engages with cam48, on the main shaft 30. Similarly arm 49 is secured toshaft 41 andconnected by link 50 with arm 51 which as shown on Figure 3 is alsopivoted on stud 46, and carries roller 52, which engages with cam 53also on the main shaft 30. Arm 49 is also connected by the link 54 witharm 55, secured to -shaft 56.' This shaft also carries the sheet stop57.

The pusher 58, of which one or more may be used is pivoted on the rod59, secured to member 60, which slides on the rod 61. It will beunderstood that a similar member and rod are used at the other side ofthe machine.

The pusher arm 58 is maintained in operative position by the spring 58acarried on the rod 58h, one end of which is pivotally connected to thearm 58, while the other end passes freely through an adjustable bushing58e, screw threaded into the member 58e, secured to a shaft hereinafter'Ihe free end of the rod 58h is threaded and provided with lock nuts58d. The pusher arm is thus yieldingly held in position and the locknuts and the bushing provide means to adjust the position of the pusherarm and the tension of the spring.

One end of the rod 61 is pivoted on a Xed shaft 62, and the other endslides in suitable ways in the bracket 63, secured to the frame. A pin64 serves to connect the rod 6l with a link 65, connected to one arm ofthe bell crank lever 66, the other arm of whichis connected by link 6'7to one arm of bell crank lever 68, while the other arm carries theroller 69, which engages the cam '70, secured to the main shaft 30. Itwill be understood that the motion imparted to the lever 68 by the cam'70 results in alternately raising and lowering the pusher mechanismcarried on the cross rod 59.

The members 60 are reciprocated along the rods 61 by means which consistof lugs '71, loose on the shaft '72, and held in place by washer '73 andscrews '74. Rods '75 are adjustably locked to the lugs '7l by nuts '76,and connected to the arms 7'7, secured to the shaft '78. The arm '79 isalso secured to this shaft and carries the roller which engages thegrooved cam 81.

The front drops 82, are secured to the shaft 83, to which the arm 84 isalso fastened, and link 85 connects the arm 84 to one end of the bellcrank lever 86, the other end of the lever having a roller 8'7, inengagement with the cam 88, secured to the main shaft 30. The sheetstops are thus moved from the positions shown in Figure 2 to that shownin Figure l.

Side guide mechanism indicated at 89 is operated by bell crank levers9G, links 91 and bell crank levers 92 which carry rollers 93 inengagement with cams 94.- One of these side guides is provided at eachside of the machine and they serve to properly register the sheetsidewise.

The several cam rollers, except roller 80 which runs in a groove, areheld in engagement with their respective cams by springs acting on thearms carrying them. Thus the spring 95 acts on arm 45, 96 on 51,9'7 on68,98 on 86 and 99 on 92, there being two springs 99, one on each sideof the machine.

In operation, a sheet of the material to be printed is placed on thefeed table 13 and against the sheet stop 5'7. At the proper time, thestop is raised and the roller 31 descends and presses ing sheet.

the sheet against the moving roller 22 with suicient force that it movesforward along the sheet guide 14. Before the rear edge of the sheet haspassed the roller 31, the roller 32 will have descended and press thesheet against the roller 23, thus continuing the forward motion of thesheet.

While the sheet is thus moving forward along the sheet guide, theposition of the various elements of the machine are as shown in Figure2, the pusher mechanism being depressed below the path of the sheet.When the sheet has passed the pusher arm 58, the pusher arm will beraised and moved forward engaging the rear edge of the sheet. At thesametime, the drop roller 32 is raised, and immediately thereafter the frontdrop 82 is moved out of the path of the oncom- The pusher meanwhilecontinues its motion, pushing the sheet forward to the printingfcylinders where it may .be engaged by the grippers 1'7 as shown.

In normal operation, the leading edge of the sheet reaches the frontdrops 82, just as they start tomove forward. At the same instant, theends of the gripper ngers pass the leading edge of the sheet with but avery small clearance, and then start to close. In closing, the ends ofthe fingers move over the sheet which is being advanced by the pusher ata rate slightly above the peripheral speed ofthe printing cylinders,

and grip the sheet while it is still being acted on by the pusher.

If one of the forwarding rollers should fail to properly engage a sheetand it is forwarded askew, the leading portion of the forward edge ofthe sheet will strike one of the front drops 82, and be detained untilthe action of the pusher brings the sheet into engagement with the otherdrop also. At that instant, the front drops start to swing forward, andoperation continues under normal conditions.

It will thus be understood that the front drops act to obstruct thepassage of an improperly fed sheet until the gripper fingers havepassed, and are in position to close on it.

As the speed of the pusher is greater than the peripheral speed of thecylinder and as the grippers move toward the sheet in closing, theforward edge of the sheet is pressed against the registering stops ofthe grippers, and when they close, the sheet is so held that it will beaccurately positioned on the cylinder. The pusher arms being springsupported will yield and thus compensate for any variation in the sizeof the sheet, meanwhile pressing it firmly against the registering stopsof the grippers.

It will be noted that from the time the sheet starts from the feedtable, until it is printed, that it is constantly held and propelledforward by the feeding mechanism. In consequence the printing isregistered with great accuracy.

In cases where an automatic feeder is used the feed table 13 and sheetstop 5'7 are omitted and the sheet is fed directly to the forwardingroller 22 by the sheet forwarding mechanism of the automatic feeder.Such an arrangement is shown in Figure 6, which is an outline drawingshowing an automatic feeder operatively connected to a printing machineof this class. The feeder is indicated generally by the numeral 100. Thefeeder mechanism takes the sheets singly from the pile 101, forwardsthem along the guides 102, and presents them to the forwarding roller 22of the printing machine in the proper timed relation to the movements ofthe machine, so there is no pause in the travel of the sheet from thetime it is taken from the pile until it is printed.

Figure 6 also shows an elevating table indicated at 103 on which a pileof sheets may be placed when they are to be fed to the machine manually.

What I claim is:

l. The combination with a cylinder having a plurality of registeringgrippers for aligning a sheet of relatively stiff material, of a sheetfeeding device having a sheet guide, a feed table in alignmenttherewith, a reciprocating pusher having an arm adapted, during itsforward stroke,'to engage the rear edge of a sheet and advance it alongthe guide to the grippers, forwarding rollers arranged to advance thesheet along the guide and into position to be engaged by the pusher arm,and means to depress the pusher arm beneath the guide during its returnstroke.

2. In a printing machine of the class described, a feed table, a sheetguide, means to engage a sheet near its leading edge and forward it fromthe feed table and along the guide, a second forwarding means to whichthe sheet is forwarded by the first named means and whichuninterruptedly continues the forwarding movement, a pusher which actson the sheet after it passes the,

second forwarding means, and printing -cylinders having registeringgrippers to which the sheet is forwarded by the forwarding means'and thepusher.

3. In a printing machine of the class described, a sheet guide, aforwarding roller and a drop roller co-acting therewith to forward asheet along the guide, a second forwarding roller and a second droproller co-acting therewith to forward the sheet beyond the zone throughwhich the first named roller forwards it, a pusher which engages thesheet, and printing cylinders having registering grippers to which thesheet is uninterruptedly forwarded by the forwarding rollers and thepusher.

4. In a printing machine of the class described, a feed table, a sheetguide in alignment therewith, a forwarding roller and a drop rollercoacting therewith to forward a sheet along the guld a second forwardingroller and a second drop roller co-acting therewith to forward the sheetbeyond the zone through which the rst named roller forwards it, areciprocating pusher which projects above the guide and engages thesheet on its forward stroke and recedes below the guide on its returnstroke, and printing cylinders having registering grippers to which thesheet is uninterruptedly forwarded by the forwarding rollers and thepusher..

5. In a printing machine of the class described, printing cylindershaving registering grippers, a sheet guide and forwarding rollers inalignment therewith arranged to receive a sheet and advanceit along theguide, and a pusher which engages the rear edge of the sheet anduninterruptedly advances it to the printing cylinders.

6. In a printing machine of the class described, an impression cylinderhaving a plurality of registering grippers for aligning a sheet ofrelatively stiff material, sheet guides, a feed table in substantiallyhorizontal alignment with the sheet guides, a forwarding roller and adrop roller coacting therewith to take a sheet from the feed table andforward it along the guides, and a pusher arranged to overtake the sheetas it is moving forward and engage its rear edge to push it forward tothe grippers. A

7. In a printing machine of the class described, 105 an impressioncylinder having registering grippers, sheet guides, a feed table insubstantially horizontal alignment with the sheet guides, a ilrstforwarding roller and a rst drop roller coacting therewith to take asheet from the feed table and forward it along the guides, a secondforwarding roller and a second drop roller coacting therewith to forwardthe sheet beyond the zone to which the first forwarding roller advancedit, and a pusher arranged to overtake the sheet as it is moving forwardand engage its rear edge to push it forward to the grippers.

IRVING A. HUNTING.

